Hot-air engine.



No. 856,102. PATENTED JUNE 4. 1907.

' o. EINGBOM.

EOT AIE ENGINE.

APPLIGATION P'ILED JULY 17, 1905.

INVE NTOR:

UNiTED STATES 4PATENT oEEioE.

oSSiAN EiNeBoM, or BoEeA, RUSSIA, AsSieNoE To ANDERS eUSTAE ADLEEoEEUTZ,or SKUEU, FINLAND, RUSSIA.

HOT-AIR ENGINE.

Specification of Letters Patent.

Patented June 4, 1907.

To r/,ZZ 1.1] 71/0111/ 711 may concern.-

Be it known that I, OSSIAN RINGBOM, a subject of the Czar of Russia,residing at Borg, Finland, have invented certain new and usefulImprovements in Hot-Air Engines, of which the following is aspecification.

The aim of the present invention is to produce a hot air engine in whichthe movement of the displacing piston is obtained without the connectionof rods or cranks or eccentrics or other mechanical parts of the engine,but solely by the expansion of the heated air and the weight of thepiston; and to obtain at the same time a simple regulating device forthe velocity. Such an engine can be cheaply manufactured and works verywell where small power is required.

A construction embodying the invention is illustrated in theaccompanying drawings.

Figure 1 of the drawings is a vertical sec-l tion of the engine, andFig. 2 is a cross-section on the line A-B of Fig. 1.

Referring to the machine illustrated, the working cylinder 1 is providedwith the usual or any suitable piston connected by a link and crankshaft to a fly wheel. In one side of the cylinder 1 there is an opening2 through which the air can enter the working chamber of the cylinderwhen the piston passes below' the opening. The upper part of the workingcylinder is connected with the pressure generator by means of a tube 3.rI`he pressure generator consists of an upper half 4 and a lower half 5which are separated from each other by a Vring-shaped packing or heatinsulator 6 of any suitable insulating material. The upper half isprovided with a cooling jacket 7,. Between the jacket and the innershell water is circulated in order to keep the upper part of thegenerator cool. Any suitable means may bel provided for circulating thewater, such as the pump and connections indicated diagrammatically.

The lower half of the pressure cylinder extends into a furnace 8 whichhas a grate 9 and an opening 10 for introducing the combustiblematerial. The combustion gases surround the lower part of the pressuregenerator and pass out through an opening 11 into any convenientchimney. In order to obtain a considerable heating surface the lowerhalf 5 of the generator is provided with ribs 12 preferably cast thereonas indicated in Fig. 2. The generator is preferably a cylinder ofcircular crosssection and within it is a displacer in the form of apiston comprising two parts 13 and 14 separated by a heat insulator 15.The piston fits loosely in the cylinder so as to move freely up anddown. vThe lower part of the piston is highly heated by the sur'-rounding heated portion of the cylinder, and the upper part is similarlycooled. The heat insulator between the two parts of the piston preventsthe transmission of heat to the upper part, whereby the lower partserves .as an auxiliary heating means and the upper part as an auxiliarycooling means. The heating and coolingsurfaces are thus nearly doubledeven though the auxiliary heating means has a lower and the auxiliarycooling means a higher temperature than the adjacent portions of thecylinder.

The air-displacing piston is provided at its upper end with a guide rod16 which passes through a guide 17 attached to the outside of thegenerator cylinder. The guide rod is provided at its point of connectionwith the displacer with a ring Ior collar 18 which fits exactly in asocket 19 provided in the end of the cylinder and the adjacent part ofthe guide 17. At the upper end of the guide rod there is a ring 20 whichis fastened on the rod by means of a nut 21 and in its lowest positionenters a corresponding hollow or socket in the end of the guide 17, andis carried at such a point that there is always a Spacebetween thedisplacer piston and the bottom of the generator chamber. By themanipulation of this nut a regulation of the out-put of the engine toany desired extent is made possible, as is described in detailhereinafter.

The operation of the engine is as follows The motor is started by meansof the ily wheel. When the working piston in the cylinder 1 passes belowthe opening 2 air enters the cylinder 1 from the outside, and, on thereturn of the piston after the closing of the opening air is forced bythe working piston into the pressure generator 4, 5, under slightcompression. The greater portion of the air passes naturally to thecooled, upper, free chamber. By a proper proportioning of the dimensionsof the working cylinder, the displacer piston and the guide rod, I caninsure that at a suitable instant, when the working piston is near itsdead point, the pressure on the bottom of the displacer piston isgreater than the total pressure on the top (since the IOO 'vantage ofthe present engine.

pressure surfaceis reduced by the cross-sectional area of the guide rod)and the weight of the several parts of the displacer piston as well asthe friction of the guide rod in its guide. At this instant thedisplacer rises. The collar 1S enters the socket 19, whereby the aircushion formed in said socket takes up the shock. Vhereas the heat ofthe lower part of the generator cylinder previously had proportionatelylittle influence on the compression of the air, since the air waschiefly in the upper cooled part of the cylinder, now on the other handthe proportion changes. The greater part of the air being in the lowerpart'of the generatorcylinder the degree of compression rises quickly,acting as a brake on the working piston, and when the working pistonwith the help of the fly wheel has passed its dead point, driving theworking piston down again. In this downward movement of the workingpiston the air expands again. It is to be observed that the heating andexpansion of the air occur particularly at the moment when the displacerrises and the air falls between the heated walls constituting the lowerportions of the displacer piston and its surrounding cylinder. Also,however, while the air continues to drive the working piston and toexpand, there occurs, though to a less extent, a considerable heating ofthe air in the lower part of the generator, which heating makes up forthe loss of pressure by expansion in the working cylinder. When the sumof the pressure on the top of the displacer and the weight of theseveral parts thereof exceeds the sum of the pressure from below and thefrictional vresistance of the guide, the displacer again falls back toits starting position and the ring 20 forms an air cushion in the socketin the topof the guide 17, which reduces the shock. The instant at whichthe falling of the dis-q placer shall occur can be determined by aproper dimensioning of the collar 18 and the corresponding socket 19.vThis easy and desirable determination of the instants when the displacerrises and falls is an especial ad- When' the displacer falls the air inthe generator again goes to the top and is here again cooled and mademore dense. Just as in the downward passage of the air in the narrow waybetween the displacer and the generator cylinder a quick heating andexpansion took place, so the opposite action now takes place quickly inthe upward passage of the air between the two cooled surfaces. Thisoccurs, however, at the latest at the instant when the working pistonpasses the opening 2. By reason of the cooling of the air in the upperpart of the generator and the further movement of the working piston avacuum is obtained within the apparatus and new air is sucked in. Theworking piston is carried past the dead point with the help of the Hywheel, and

moves again upward past the opening 2 and the previously describedoperation is repeated.

This hot air engine possesses the peculiarity of having no mechanicalconnection between the displacer piston and the working piston. In mymachine the movable masses are reduced,--a matter of great importancefor obtaining high speed. The thing requisite for the working of theengine is only that the iire shall be strong enough to secure the quickheating in the lower part of the pressure generator. By means of the nut21, as above explained, a certain regulation of the piston velocity andof the out-put can be obtained, since the starting point of thedisplacer can `be made higher or lower. This regulation dependsprincipally on the fact that the greater quantity of air under thedisplacer when the latter is at a higher point, causes a greaterincrease of compression than when the displacer is in its lowestposition.

The compression will therefore be of a degree corresponding to theheight of the displacer. The resulting strong increase of pressure,corresponding to the compression and back pressure of a steam engine,occurs sooner and acts more strongly as a brake against the workingpiston.

The cylindrical heating surface of the generator is in direct proportonto the extent to which it dips into the iire box. If it dips to a lessextent the heating surface is also less, and the quantity of heat whichthe air will receive and the quickness of the expansion are less). To besure the air, if the displacer be supposed arranged at a higher point inthe furnace, will remain somewhat longer in the bottom of the generatorcylinder, which is in the top of the iire box, and will thereby receivea longer and more effective heating than otherwise. Nevertheless it isapparent lfrom the several considerations mentioned that the less deeplythe generator dips into the iire box the greater the reduction ofefi'lciency. The out-put of the engine becomes less and the velocityalso. The exact position of the insulating layer 15 for greatestefiiciency of the engine may be modified ac` cording to circumstances. y

Various other modifications may be made in detail and in the arrangementand combination of the parts without departure from the invention.

Vhat I claim is 1. A hot air engine, including, in combination, an airdisplacer and a working piston disconnected mechanically from eachother, a pressure generating chamber in which said displacer works, aworking cylinder in which said piston travels, and a conduit fortransmitting the excess of pressure in the generator to the workingpiston to drive the same, said working cylinder being provided with anorifice at a suitable height such that air IOO IIC

l A hot air engine, including, in combination, an air displaoer and aworking piston disconnected mechanically from each other, a cylindricalpressure generating chamber in which said displacer works, a workingcylinder in which said piston travels, and a conduit for transmittingthe excess of pressure in the generator to the working piston to drivethe same, said displacer comprising i a piston fitting loosely in thecylindrical pres sure generator and guided by a rod 16 eX- [5 tendingoutside of said generator, and a nut 21 on said rod for determining theheight of the lowest position of the displacer.

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing zo witnesses.

OSSIAN RINGBOM.

Witnesses: 4

F. KoLsTER, OSCAR EKsTRoM.

